This is a request to purchase a Jasco J500C automatic recording spectropolarimeter, which will provide the capability of measuring circular dichroism spectra of biological molecules with the view of obtaining conformational information. Such a facility does not presently exist in the city of San Antonio. In fact, the closest CD facility is 200 miles away which precludes its use as a serious and ongoing research tool. The requested instrument would be housed in the Department of Biochemistry at The University of Texas Health Science Center at San Antonio. Although a wide variety of distinct experiments will make use of this facility, the following studies of the core users group is representative: 1. Structure-Function Studies of Thiosulfate Sulfur Transferase (TST). 2. The Structure and Behavior of Tubulin. 3. Circular Dichroism Studies of Membrane Lipoproteins. 4. CD Studies of Calcium Regulatory Proteins from Human Erythrocytes. 5. CD Studies of Human Terminal Complement Complexes. 6. The Structure and Reactions of Pseudomonas Cytochrome Oxidase.